The discovery of glass can be accredited to ancient Mesopotamia, though glass vessels did not appear until the late sixteenth century BC. This jar was made in the Byzantine Empire – glass wares were among the goods most frequently produced during this time, and followed the print of their Roman predecessors. Most of the Byzantine glass workshops were in Thessaloniki, a centre of production from the late Roman imperial period onwards.
The iridescence on ancient Roman glass was unintentional, and was caused by weathering on its surface. The extent to which a glass object weathers depends mainly on the burial conditions; however, the humidity, heat, and type of soil in which the glass was buried also all affect its preservation.